<form nz-form [formGroup]="belongForm" (ngSubmit)="submitForm()">
  <nz-form-item>
    <nz-form-label [nzSm]="6" [nzXs]="24" nzFor="belongto" nzRequired>所属上级</nz-form-label>
    <nz-form-control [nzSm]="14" [nzXs]="24">
      <nz-select formControlName="belongto">
        <nz-option nzLabel="Jack" nzValue="jack"></nz-option>
        <nz-option nzLabel="Lucy" nzValue="lucy"></nz-option>
        <nz-option nzLabel="Tom" nzValue="tom"></nz-option>
      </nz-select>
    </nz-form-control>
  </nz-form-item>
</form>